• Title/Summary/Keyword: Direct Frequency Analysis

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An Analysis of TX/RX Microstrip Single Element using FDTD at Ku-band and 8X4 Array Antenna (FDTD 방법을 이용한 Ku 대역 송수신 겸용 마이크로스트립 단일 소자 해석 및 8X4 배열 안테나)

  • 윤재승;전순익
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.14 no.8
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    • pp.830-838
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    • 2003
  • In this paper, TX/RX dual operation microstrip single antenna for satellite communication is designed, analyzed, fabricated and measured. TX/RX frequency ranges are 14.0∼l4.5 GHz, 11.7∼12.75 GHz in respectively and vertical and horizontal polarizations are used for TX and RX. This antenna uses microstrip direct feeding for RX and aperture coupled strip-line feeding for TX and accommodates stacked elements for a high directivity and wide impedance bandwidth. In an analysis of single element, FDTD and MOM was compared and FDTD analysis was more accurate because of the consideration of finite structure and imperfect two ground planes. The proposed structure facilitates generally to an extension of two dimensional array and lower an unwanted radiation by strip-line feed in TX. TX/RX 8${\times}$4 array has a return loss below -10 dB, -14 dB in TX, RX respectively and a gain ranging from 19.1∼20.7 dB in TX, 21.2∼21.8 dB in RX which has a radiation efficiency of 43∼5l %, 52∼57 %.

The Structural Model Suicidal Ideation in Elderly Living Alone (독거노인의 자살생각에 대한 구조모형 분석)

  • Kim, Jeong-Suk
    • Journal of Convergence for Information Technology
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    • v.8 no.2
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    • pp.29-36
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    • 2018
  • This study was conducted to analyze the model of suicide ideation in the elderly living alone. This study is a descriptive research study of 300 elderly living alone in C-region. It is a frequency analysis, correlation analysis, simple rare analysis. AMOS statistics were performed. Data collection was from October 1, 2016 to December 31, 2016. The results of this study are as follows. Family support has a direct effect on suicidal ideation(need for suicide ${\beta}=-.362$, p=.000, negative attitudes toward life ${\beta}=-.259$, p=.001). The results of this study suggest that strengthening the family support and social activities of the elderly living alone reduces the suicidal ideation and builds the social safety net, which leads to the emotional stability and the related policy establishment.

Studies on the Hand Hygiene Practices of Food-Service Businesses Workers: A Comparison of Full-time and Part-time Workers (외식업소 종사자의 손 위생관리에 관한 연구)

  • Kim, Jong-Gyu;Park, Jeong-Yeong;Kim, Joong-Soon
    • Journal of Environmental Health Sciences
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    • v.39 no.1
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    • pp.71-82
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    • 2013
  • Objectives: This study was performed in order to investigate hand hygiene practices among food-service businesses employees based on the awareness of hand-washing and load of indicator bacteria on their hands. It focused on the comparison of full-time and part-time workers in food-service workplaces. Methods: A direct-interview questionnaire survey and microbiological analysis were carried out with sixty workers each. Samples for microbiological analysis were collected through a modified glove-juice method from the hands of the food-service workers and were analyzed for aerobic plate count, total coliform, fecal coliform, Escherichia coli, Staphylococcus aureus, and Salmonella spp. Microbiological analysis was done according to the Food Code of Korea. Results: Significant differences (p<0.01) were found in the survey between the full-time and part-time workers in hand-washing frequency, use of hand-washing agents, and hand-drying methods. More full-time workers responded to washing their hands after preparing food, after visiting outside, after handling raw materials, and before putting on gloves/when changing gloves than did part-time workers (p<0.05). No remarkable difference was found in bacterial load on the hands except in the aerobic plate count between the two groups. The detection of E. coli, S. aureus, and Salmonella spp. on the hands of some food-service workers in both groups revealed poor hand hygiene practices. Conclusions: The results of this study indicate that there is a need for training programs in order to improve hand hygiene practices and strict hand hygiene compliance by food-service workers.

Analysis of a fixed source-to-receiver underwater acoustic communication channel parameters in shallow water (송수신기가 고정된 천해 수중음향통신 채널 매개변수 해석)

  • Bae, Minja;Park, Jihyun;Yoon, Jong Rak
    • The Journal of the Acoustical Society of Korea
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    • v.38 no.5
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    • pp.494-510
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    • 2019
  • Underwater acoustic communication channel parameters consist of impulse response, delay spreading, scattering function, coherence bandwidth, frequency selective fading, coherence time and time variant magnitude fading statistics on which communication system modem and channel coding are designed. These parameters are influenced by sound velocity profile, platform motion and sea surface roughness in given acoustical oceanography condition. In this paper, channel model based on phasor, channel simulator, measurement and analysis method of channel parameters are given in a fixed source-to-receiver system and the parameters are analyzed using shallow water experimental data. For two different source-to-receiver ranges of 300 m and 600 m, the parameters are characterized by three multipaths such as a direct, a surface reflection path with time variant scattering and a bottom reflection path. The results present a channel modelling method of a fixed source source-to-receiver system, channel parameters measurement and analysis methods and a system design and performance assessment method in shallow water.

The Impact of Technology Utilization on Health Research and Development: Case Studies of the Development of Medical Device (합리적 기술 활용이 연구개발에 미치는 영향: 의료기기 개발 사례를 중심으로)

  • Min, Hye Sook;Park, Ji Eun;Kim, Chang-Yup
    • Health Policy and Management
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    • v.31 no.2
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    • pp.148-157
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    • 2021
  • Background: Based on that the key function of health technology is improving the quality of healthcare services, our study purports to explore the process of medical device development in detail and to discuss its policy implications. Methods: A total of 12 in-depth interviews were conducted with four groups of industry, hospital, academia, and civil society. All of the interviewees except those from civil society were involved in the new medical device development between 2009 and 2018. We performed a text network analysis and content analysis of the interview data. Results: The frequency and the degree centrality rankings suggested a close association between the utilization issue and the technology development. Similarly, the results of the content analysis showed that the appropriate intervention in the utilization of technology has a direct impact on the progress of development. Under the continuous industrial effort to boost profits by developing new technology, service providers and citizens should be knowledgeable of and make good use of the new technology for the provision of better services. Conclusion: As the development itself would not guarantee the improvement of service quality and better health outcomes, health technology policies should take a more comprehensive view to serve the unmet needs and even to facilitate the technology development.

Factors driving Fashion Chatbot Reliability -Focusing on the Mediating Effect of Perceived Intelligence and Positive Cognition- (패션상품 챗봇에 대한 신뢰 형성 요인 - 지각된 지능과 긍정적 인지의 매개효과를 중심으로 -)

  • Lee, Ha Kyung;Yoon, Namhee
    • Fashion & Textile Research Journal
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    • v.24 no.2
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    • pp.229-240
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    • 2022
  • This study explores the effect of anthropomorphism on fashion chatbot reliability, mediated by perceived intelligence and cognitive evaluation. The moderating effects of individuals' need for human interaction between chatbot anthropomorphism and perceived intelligence, cognitive evaluation, and chatbot reliability are also explored. Participants, who were recruited through the online research firm, responded to questions after watching a video clip showing a conversation with a fashion chatbot on a mobile screen. The data were collected through Mturk, a crowdsourcing platform with an online research panel. All responses (N = 212) were analyzed using SPSS 26.0 for the descriptive statistics, frequency analysis, reliability analysis, exploratory factor analysis, and PROCESS procedure. The results demonstrate that chatbot anthropomorphism increases chatbot reliability, and this is mediated by chatbot intelligence. Although chatbot anthropomorphism increases cognitive evaluation, the effect of cognitive evaluation on chatbot reliability is not significant; thereby, the effect of chatbot anthropomorphism on chatbot reliability is not mediated by the cognitive evaluation. The direct effect of anthropomorphism on chatbot reliability is also moderated by individuals' need for human interaction. For participants with a high need for human interaction, chatbot anthropomorphism increases chatbot reliability; however, anthropomorphism does not significantly affect chatbot reliability for participants with a low need for human interaction. The study's findings contribute to expanding the literature on consumers' new technology acceptance by testing the antecedents affecting service reliability.

Assessment of extreme precipitation changes on flood damage in Chungcheong region of South Korea

  • Bashir Adelodun;Golden Odey;Qudus Adeyi;Kyung Sook Choi
    • Proceedings of the Korea Water Resources Association Conference
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    • 2023.05a
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    • pp.163-163
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    • 2023
  • Flooding has become an increasing event which is one of the major natural disasters responsible for direct economic damage in South Korea. Driven by climate change, precipitation extremes play significant role on the flood damage and its further increase is expected to exacerbate the socioeconomic impact in the country. However, the empirical evidence associating changes in precipitation extremes to the historical flood damage is limited. Thus, there is a need to assess the causal relationship between changes in precipitation extremes and flood damage, especially in agricultural region like Chungcheong region in South Korea. The spatial and temporal changes of precipitation extremes from 10 synoptic stations based on daily precipitation data were analyzed using the ClimPACT2 tool and Mann-Kendall test. The four precipitation extreme indices consisting of consecutive wet days (CWD), number of very heavy precipitation wet days (R30 mm), maximum 1-day precipitation amount (Rx1day), and simple daily precipitation intensity (SDII), which represent changes in intensity, frequency, and duration, respectively, and the time series data on flooded area and flood damage from 1985 to 2020 were used to investigate the causal relationship in the ARDL-ECM framework and pairwise Granger causality analysis. The trend results showed that majority of the precipitation indices indicated positive trends, however, CWD showed no significant changes. ARDL-ECM framework showed that there was a long-run relationship among the variables. Further analysis on the empirical results showed that flooded area and Rx1day have significant positive impacts on the flood damage in both short and long-runs while R30 mm only indicated significant positive impact in the short-run, both in the current period, which implies that an increase in flooded area, Rx1day, and R30 mm will cause an increase in the flood damage. The pairwise Granger analysis showed unidirectional causality from the flooded area, R30 mm, Rx1day, and SDII to flood damage. Thus, these precipitation indices could be useful as indicators of pluvial flood damage in Chungcheong region of South Korea.

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Study on the Influence of Growth Mindset of University Students on Occupational Engagement: Testing the Mediation Effect of Career Adaptability (대학생의 성장마인드셋과 진로관여행동의 관계에서 진로적응성의 매개효과 검증)

  • Woojung, Jang
    • Journal of Industrial Convergence
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    • v.21 no.3
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    • pp.49-56
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    • 2023
  • The purpose of this study is to verify the mediating effect of career adaptability in the relationship between growth mindset and occupational engagement. A total of 203 data were collected through an online survey targeting university students. For data analysis, frequency analysis and descriptive statistics analysis were used via SPSS 25.0 and AMOS 25.0 software. As a result of the study, growth mindset had a direct effect on occupational engagement (𝛽=.254, p<.01) and the mediating effect of growth mindset on occupational engagement through career adaptability was also statistically significant. (𝛽=.137, p<.01). This study suggests that it is important to promote occupational engagement for students' correct career guidance, and to this end a practical strategy for cultivating a growth mindset and career adaptability is needed.

Investigation on organizational culture and sexual harassment in the workplace of dental hygienists (치과위생사의 직장 내 조직문화와 성희롱 실태조사)

  • Ji-Hyoung Han;Ji-Min Hwang
    • Journal of Korean Academy of Dental Administration
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    • v.11 no.1
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    • pp.8-18
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    • 2023
  • The purpose of this study is to examine the organizational culture of dental hospitals and clinics, as well as to assess members' perceptions and actual conditions related to sexual harassment. The research method involved conducting a cross-sectional survey of 149 dental hygienists using random sampling. The analysis utilized frequency analysis and descriptive statistical analysis. Regarding awareness of organizational culture within the workplace, 39.6% responded, "It is difficult to freely use maternity and childcare leave at our workplace". When asked about sexual harassment, 51.7% of respondents said they had received training on sexual harassment prevention. The highest level of sexual harassment experienced was "sexual analogy or evaluation of appearance", at 45.8%. The most common perpetrators of sexual harassment were agency heads and directors, at 37.5%. The most common behavior of the victim at the time was "changing the subject or avoiding the scene" (41.7%). 50.0% of victims of sexual harassment responded to the harm by "just putting up with it". The most common response to the direct and indirect impact of sexual harassment was "there was no specific impact". The most common response from the agency was "there were no suitable measures". Regarding the most necessary policy to prevent sexual harassment, "strict punishment for perpetrators (37.5%)" was the highest. There is a need for organizational and cultural changes to reduce sexual harassment in the workplace. Additionally, it is crucial for the country and society as a whole to actively participate in and improve the system.

Fishermen's Perceptions and Considerations regarding the Coexistence of Fishing Activities within Offshore Wind Farms

  • Yu-Jeong Mun;Cho-Young Jung
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.30 no.3
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    • pp.283-290
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    • 2024
  • In this study, a survey on the coexistence of offshore wind farm and fishing activities in Gochang, Gunsan, and Buan's fishermen in the southwest sea of shore wind farm was carried out witn an aim of examining the factors that should be considered when coexisting. A questionnaire was composed after referring to domestic and foreign literature data on examples of coexistence. The questionnaire was issued through direct visits. Frequency analysis and cross-analysis were used for survey response results, and IBM SPSS Statistics ver. 26 was used for statistical processing. As a result of analyzing a total of 84 questionnaires, the perception of the coexistence of offshore wind and fishing activities was the same by 50.0% positive and negative, respectively. As a result of cross-analysis by region, significant differences were found (p <0.039). Gochang fishermen showed a high negative perception of the coexistence of offshore wind and fishing activities at 62.1%, with the main reason being that fishing resources are expected to decrease due to the influence of noise, vibration, and current generated from offshore wind farm facilities. In Gunsan, negative perception of coexistence was high at 57.7%. This was mainly attributed to the impossibility to operate in the offshore wind farm due to the nature of the fishery. On the contrary, in the case of Buan, 69.0% of the positive perception of coexistence was high 'because fishermen were dissatisfied with the current coexistence plan (policy)'. According to previous studies, 91.8% of domestic fishing methods show the possibility of fishing activities in offshore wind under caution, so it is concluded that research should be conducted to coexist with offshore wind and fishing activities as in foreign countries for smooth installation of offshore wind and continuous fishing activities.